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UNIVERSITY OF CALIFORNIA Agricultural Experiment Station 

College of Agriculture e. w. hilgard, director 



(June, 1903.) 



Veterinarian and Bacteriologist. 

Symptoms. — It is quite impossible to mention a series of symptoms to 
be relied upon always in recognizing the disease. The name is mis- 
leading, in that the bowels are not necessarily loose, but a diarrhea is 
most common. There may be constipation. Such animals are spirit- 
less and generally do not stir about. In advanced cases there is a 
staggering gait. There is frequently trouble with the eyes, causing a 
discharge, and there may be a reddening of the skin on various parts of 
the body. Some die of an acute type of the disease within a few days 
after coming down, while others will suffer for weeks from a chronic 
(mild) form. 

Post-Mortem Appearances. — The most constant of the diseased altera- 
tions of the carcass is the presence of little red spots sprinkled over 
the various organs. They are found on the kidneys, on the intestines, 
or stomach, heart, diaphragm, lungs, or the lining of the lung or intes- 
tinal cavities and elsewhere. Little glands colored red by blood are 
found scattered along the membrane that attaches the intestines to the 
back. The spleen is enlarged and darkened in color. In cases of long 
standing there may be found ulcers on the inside of the intestines. 
They are circular in shape, project slightly, and are grayish-yellow or 
black in color. These ulcers are most apt to be found in the large intes- 
tine. If ulcers are found, it is usually safe to conclude that the disease is 
hog cholera, but the absence of them is not significant. The lungs are 
not commonly seriously diseased, but may be solidified in spots. 

How Hog Cholera Is Spread. — The disease is caused by germs which 
are responsible for its existence and spread. The germs are present in 
the intestinal discharge of the sick, and consequently the disease spreads 
rapidly when introduced among pigs. Hog cholera can be prevented 

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by paying strict attention to the various means by which it is spread 
from the sick to the healthy. Chief among these are : 

1. Purchase of hogs from diseased herds. The animals may be 
actually suffering from a mild attack of cholera or they may convey 
the germs upon the filth adhering to their bodies. 

2. Railroad shipping-pens, cars, and other inclosures may harbor 
infecting material dropped by diseased hogs in transit. 

3. There is an overwhelming amount of evidence showing that the 
disease may be carried by streams of water. A very fruitful means of 
spreading the disease is to throw a dead hog in a stream or to allow 
diseased hogs to have access to a stream. 

4. The germs may be carried from the diseased to the healthy by the 
filth adhering to the shoes of a man, the feet of a dog, or farm utensils. 
When hog cholera is prevalent in a community, owners of healthy hogs 
should not go among sick hogs, because of the danger of carrying the 
infection home. 

5. Buzzards and other carrion birds and animals may spread the 

A few pigs only are affected when the disease first breaks out, and if 
they are noticed and prompt action taken the spread may be checked. 
The healthy ones should be removed from the pens or field where the 
disease has appeared, and be given a supply of well water. Animals 
kept in small inclosures are less apt to contract the disease than 
those running on large areas of land, as they are usually allowed to do 
in California. Wallowing-holes of mud are conducive to the spread of 
the disease. The dead should be burned or buried in quicklime. 

Buildings, feeding-troughs, and land contaminated by sick pigs will 
harbor the disease for many months. After an outbreak the disinfection 
of buildings and feeding-troughs is necessary before introducing healthy 
hogs. The following is a good cheap disinfectant: 

Crude carbolic acid K gallon. 

Crude sulfuric acid ..- K gallon. 

" These two substances should be mixed in tubs or glass vessels. The 
sulfuric acid is very slowly added to the carbolic acid. During the 
mixing a large amount of heat is developed. The disinfecting power is 
heightened if the amount of heat is kept down by placing the tub or 
demijohn containing the carbolic acid in cold water, while the sulfuric 
acid is being added. The resulting mixture is added to water in the 
ratio of 1 to 20. One gallon of mixed acid will thus furnish 20 gallons 
of a strong disinfecting solution, having a slightly milky appearance. 
The mixture should be applied to the walls and floors of the pens, sat- 
urating them with it." 

Small yards may be disinfected with slaked lime. Extensive ranges 
are preferably not used for a year, although some authorities place the 

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period for the eradication of infection by natural climatic agencies at 
six months. 

Treatment. — There is no medicinal treatment that can be relied upon 
to cure every case of hog cholera. In numerous cases medicines have 
been administered and the animals have recovered, but such an occur- 
rence does not prove that the medicine induced the favorable change. 
It is a matter of common observation that the violence of the disease 
may abate very abruptly without apparent cause. 

Much can be done to ward off the disease and perhaps to cure mild 
cases by the use of the following medicine recommended by Dr. D. E. 
Salmon, Chief of the Bureau of Animal Industry of the United States 
Department of Agriculture: 


Wood charcoal 1 

Sulfur 1 

Sodium chlorid... _ _ _ _ 2 

Sodium bicarbonate... _ 2 

Sodium hyposulfite _ 2 

Sodium sulfate 1 

Antimony sulfid (black antimony) ._ 1 

" These ingredients should be completely pulverized and thoroughly 
mixed. In case there is a diarrhea the sulfate of sodium may be 

" The dose of this mixture is a large tablespoonful for each 200 pounds 
weight of hogs to be treated, and it should be given only once a day. 
When hogs are affected with these diseases they should not be fed on 
corn alone, but they should have at least once a day soft feed, made by 
mixing bran and middlings, or middlings and corn meal, or ground oats 
and corn, or crushed wheat with hot water, and then stirring into this 
the proper quantity of the medicine. Hogs are fond of this mixture, it 
increases their appetite, and when they once taste of food with which it 
has been mixed they will eat it though nothing else will tempt them. 

"Animals that are very sick and that will not come to the feed should 
be drenched with the medicine shaken up with water. Great care 
should be exercised in drenching hogs or they will be suffocated. Do 
not turn the hog on its back to drench it, but pull the cheek away from 
the teeth so as to form a pouch, into which the medicine may be slowly 
poured. It will flow from the cheek into the mouth, and when the hog 
finds out what it is, it will stop squealing and swallow. In our experi- 
ments hogs which were so sick that they would eat nothing have com- 
menced to eat very soon after getting a dose of the remedy, and have 
steadily improved until they appeared perfectly well. 

" This medicine may also be used as a preventive of these diseases, 
and for this purpose should be put in the feed of the whole herd. Care 
should of course be observed to see that each animal receives its proper 

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share. In cases where it has been given a fair trial, it has apparently- 
cured most of the animals which were sick and has stopped the progress 
of the disease in the herds. It also appears to be an excellent appetizer 
and stimulant of the processes of digestion and assimilation, and when 
given to unthrifty hogs it increases the appetite, causes them to take on 
flesh and assume a thrifty appearance." 

The administration of the medicine is useless unless the patients are 
kept under comfortable conditions with careful feeding. 

There has been much careful experimental work done in an effort to 
produce a serum for injecting under the skin of hogs, to cure the 
cholera or to immunize the system against it. Some experiments have 
yielded satisfactory results on a small scale, but this line of treatment 
has not progressed far enough to be of practical use as yet. 

Quarantine Regulations for Hog Cholera. — Prevention of the disease 
by strict quarantine must ever be relied upon to check the enormous 
losses from hog cholera. Individuals who have carefully studied the 
disease can accomplish much by voluntarily observing the precautions 
necessary to prevent its spread. But to effectually restrict hog cholera, 
regulations with the force of law must exist, as well as a corps of men to 
enforce them. California is sadly lacking in these requisites, and until 
they are supplied the swine industry must continue to suffer appalling 
losses annually. 

As an example of the kind of measures necessary for the control of 
hog cholera there is appended a copy of a circular giving directions for 
quarantining infected animals: 


For Quarantining Hogs Suffering from any Infectious Disease. 

The proper quarantine of hOgs imposes no hardship upon either the owner or the 
hogs themselves. The chief purpose of the Board of Health in quarantining any suspi- 
cious disease among hogs is to protect the financial interests of the hog-raisers. Valua- 
ble time is often lost before quarantine is established. This permits serious spread of 
the disease to take place, and makes its control much more difficult. 

The disease now prevailing in different portions of the State varies in symptoms in 
different localities and in different herds. It may be set down as a rule, however, when 
any infectious (catching) disease appears among swine that it is hog cholera, modified 
more or less in symptoms by well-known complications. 

When hogs begin to sicken and die during the prevalence of hog cholera the disease 
should be reported to the local health officer or chairman of the town board, and quar- 
antine should be established at once. It is a simple matter to release quarantine, and 
should it be proven that the disease is not hog cholera, no harm has been done by such 

All health officers and acting health officers are therefore instructed to see that sus- 
picious outbreaks of disease among hogs are properly quarantined. 

The health officer should explain to the owner or keeper the nature and conditions 
of quarantine, and see that the conditions are rigidly enforced until quarantine is 

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Hog cholera is often spread by water in small streams and lakes, and for this reason 
hogs must not be buried near any such lake or watercourse. 

Poultry should not be allowed access to yards or pens where hogs are confined during 
the hog cholera season, and pigeons and crows should be shot or otherwise frightened 
away, because of danger that they may spread the disease. 

The health officer or inspector should always wear overalls and overshoes or rubbers 
when going among diseased hogs. These overalls and overshoes or rubbers should 
always be kept a safe distance from healthy hogs and from other agents which might 
convey the disease. 

Quarantine cards must not be removed until six months after the last hog has died 
or recovered, and the premises disinfected in a way satisfactory to the local board of 

Farmers should be urged to dispose of marketable hogs for slaughter as soon as sus- 
pected hog cholera appears in the neighborhood. 

Racks and wagon boxes used for hauling such hogs must be tight and so constructed 
at the bottom as to prevent the scattering of manure and litter along the highway. 

Racks and wagon boxes, which have been used for transporting such hogs, must be 
thoroughly disinfected as soon as the work is finished. All parts of the wagon that 
have come in contact with the hogs or litter must be thoroughly disinfected. Five per 
cent solution of crude carbolic acid in water is cheap and effective. 

Neighbors on whose farms the disease has not yet appeared should never be allowed 
to help haul the hogs from infected farms, as there is great danger that the disease will 
be spread from farm to farm by such action. 

The following placards are required to be posted in a conspicuous 
place by owners of swine in a community where the disease exists: 


Exists on These Premises. 

All persons, excepting the owner, duly authorized attendants, or medical advisers, are 
forbidden to enter any inclosures where hogs are kept on these premises, until this card 
has been removed by permission from the State or local Board of Health. 

Hogs must not be removed from these premises after date of this card, until six 
months after the last case of suspicious swine disease has died or recovered, except in 
the following cases: 1st, by permission in writing given by the State Board of Health ; 
and 2d, dressed carcasses of healthy hogs killed under inspection of the State or local 
Board of Health. 

No hogs, excepting those hereby quarantined and their offspring, shall be allowed 
upon these premises until six months after the last hog has died or recovered. During 
this period of six months no other domestic animal shall be permitted in these pens for 
any reason whatever. 

Parties living on this place must not go near pens or yards where hogs are kept on 
other farms. 

Keepers of these hogs will be held responsible for the unauthorized removal of this 
notice, and for allowing any swine hereby quarantined to escape from these pens or 
yards and run at large. 

Bv order of 

, Health Officer. 

Dated , 19—. 

Chapter 233, Laws of 1897 (Minnesota).— Section 9. Any person violating any pro- 
vision of this Act or any rule or regulation made by the State Board of Health, or by 
any local Board of Health, or any order made by any such board under the authority 
hereof, shall be guilty of a misdemeanor and be punished by a fine of not less than 
twenty-five (25) or more than one hundred (100) dollars, or by imprisonment for not less 
than thirty (30) or more than ninety (90) days. 

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[For Use by Owners of Hogs.] 


All unauthorized persons are forbidden, under penalty of the law, to approach on 
these premises nearer than 50 feet to any pens or yards where hogs are confined. 

Signature of owner. 

Chapter 233, Laws of 1897 (Minnesota).— Section 11. Whenever during the preva- 
lence in the State of any contagious or infectious disease among domestic animals, the 
owner shall post on his premises a notice forbidding all persons not authorized by State 
or local Boards of Health to enter any building or inclosure on said premises, without 
permission from said owner, it shall be a misdemeanor to enter upon such premises, 
punishable by a fine of not less than twenty-five dollars ($25) nor more than one hun- 
dred dollars ($100), or by imprisonment for not less than thirty (30) days nor more than 
ninety (90) days. 

Swine Plague. — This disease is as common as hog cholera, and most 
outbreaks of the cholera are complicated by it. The symptoms do not 
greatly differ from those of hog cholera, except that it is more commonly 
a disease of the lungs, and consequently there is apt to be coughing. 
The treatment and methods of sanitation do not differ markedly from 
those laid down for hog cholera. In consequence, the definite recogni- 
tion of the disease is not of great practical importance to the owner of 
the animal. 

Soap Powder Poisonous to Hogs. — Some deaths among hogs in New 
York State were found by Dr. V. A. Moore, of the New York State Vet- 
erinary College, to be caused by one of the soap powders in common 
use. Upon investigation it was found that the soap powder was used in 
washing dishes in a kitchen, and that the dishwater found its way to the 
hogs in swill. Carefully conducted experiments later showed that pigs 
could be killed by feeding them amounts of soap powder smaller than 
commonly used in kitchens. In cases of deaths among swine it is, 
therefore, desirable to ascertain that the food is wholesome. 


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